Tesuji And Katachi

This is an introductory article aimed especially at the weaker
player. However, some of the examples are of an advanced nature, so I
hope there is something for everyone. First of all, what are tesuji and katachi?

A "tesuji" is a clever local play, which may be either
offensive or defensive. They are usually difficult to see and frequently
work miracles!

"Katachi" - or shape - is the act of placing stones in
certain patterns to achieve maximum results. This means that two stones
do the full work of two stones, and not that of one or three.

A good knowledge of tesuji and katachi enables one to play quickly
and accurately, as only a very few alternative moves come to mind as
being good possibilities and hence need be considered for each.

As a starting point, consider Dia 1. The three stones have seven
liberties. In Dia 2 three stones are seen to have eight liberties. As a
battle depends on liberties, patterns like Dia 1 are bad and tend to
lose games quickly.

However if the triangle is filled in by a stone of the opposite
colour, as in Dia 3, then black 1 can become an excellent move. The
formation in Dia 1 is called an empty triangle, for obvious reasons.

Another essential rule is to not over-concentrate your stones.
Stones should not be joined together too early in a game. The two above
rules are best illustrated by an example. I shall try to use joseki as
examples wherever possible. Study of joseki is a vital part of Go; it
teaches katachi and tesuji applicable to the whole game.

In Dia 4 white has approached blacks stone with a small knights
move. This is the most common way of attacking the handicap stone.

Playing in contact with a stone strengthens it. So both black and
white will grow strong around their mutual contact point. It should
therefore be noted that black 2 is a defensive move; Black is satisfied
to be able to build a safe group and is prepared to let White build one
too. White replies with 3. Where should Black play his fourth move, at
A, B or C?

Answer A

This is a very bad play. Black has joined his three stones together
too early in the game.

Answer B

One way of playing, but not seen very often because though Blacks
corner becomes large it is somewhat open to invasion.

Answer C

The most common and best play. Blacks three stones exert their
maximum strength. This formation occurs all over the board many times.

Dia 6 shows the finish of this joseki. Suppose White played
elsewhere with his move 7. Now it is Blacks turn. 1 in Dia 7 is
correct. After black 3, white has to resort to a vacant triangle 4, to
escape to the centre. This is obviously a good thing for black.

Another common example where vacant triangles occur is seen in Dia
9. This splitting attack of white 1 divides the black stones. White
waits for a black mistake, considering that this is a handicap game. If
Black plays as in Dia 9 he should have no trouble in setting up a good
position. If white wants to escape he must make a vacant triangle after
black 4.

Also note that Whites move 5 in Dia 10 has a bad effect as, if
black follows the rest of the diagram, he will build up a huge wall on
the right hand side of the board. This promises him a large territory
later and makes white 1 much weaker than before.

Blacks two marked stones in Dia 13 form the eye-stealing tesuji.
The important point about this tesuji is the relation between the two
Black stones; it is of no importance whether the other stones are there
or not.

For an example of the two above proverbs the joseki of Dia 16 is
worth studying. It is an unusual variation of the small avalanche
joseki. (See issue 5, page 10.)

Up to white 12 everything is quite normal. However, black 13 is
unusual. This move is the eye-stealing tesuji. White has no choice but
to play 14. If he plays elsewhere Black will play at 16, White captures,
Black plays 15 to force white to fill in, then 14 and a ladder develops.

Black 15 threatens a snap-back at 16 and white answers. 17 is vital
to capture the two stones. The rest of this joseki is fairly obvious and
the outcome of the game* will probably depend on the survival
and use made of Blacks three stones. * [BGJ had 'come'.]

Another useful piece of advice is dont make dango'. (A dango is a
formless and solid mass of stones.) Dia 17 shows the two point high
handicap pincer. This is a common joseki and should be studied.

However, move 18 is odd. Black sacrifices, as shown, two stones 12
and 18, and builds up a large wall in exchange. Note black 26; this
effectively cuts off 15 and protects the cutting point below 14.

Suppose White plays as in Dia 18. White 7 is a bad move as black can
play the rest and now capture white if the ladder is favourable for him,
or he can pursue the white dango into the centre with great advantage
and White will be at a loss as to how to deal well with the situation.

As a final example consider Dia 19. It shows part of a game between
Rin (Meijin) as black and Sakata (Honinbo) as white. The game was played
on 1st September 1966.

Both players have a weak group resulting from a difficult invasion
into Blacks territory. The marked stone was a nuisance later as it is
not yet completely captured.

White 1 is essential. For otherwise black can play one point below
1 to capture two stones.

Black 2: Blacks obvious move is at 4. However,
he must play the 2-3 exchange first. Otherwise Dia 20 results. After 10
blacks upper group has a bad form and he will find it hard to save both
it and the lower group.